Chip on flex optical subassembly

Patent metadata

Field	Value
Publication number	US-9709760-B2
Application number	US-201615150330-A
Country	US
Kind code	B2
Filing date	May 9, 2016
Priority date	Dec 14, 2011
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

One example embodiment includes an optical subassembly (OSA). The OSA includes a flex circuit, an optical port, and an active optical component subassembly. The flex circuit is constructed of at least one electrically-conductive layer and at least one electrical insulator layer. The optical port defines a barrel cavity and is mechanically coupled to the flex circuit at a flex connection. The active optical component subassembly is positioned within the barrel cavity and electrically coupled to the flex circuit.

First claim

What is claimed is:

1. An optical subassembly comprising:
a flex circuit that includes a printed circuit board (PCB) flex connection and a flex connection, wherein the PCB flex connection is included on a first portion of the flex circuit that is opposite a second portion of the flex circuit that includes the flex connection;
an optical port that defines a fiber receiver and a barrel cavity, the optical port being mechanically coupled to the flex circuit at the flex connection on a first surface of the flex circuit;
an active optical subassembly positioned within the barrel cavity and located on the first surface of the flex circuit, wherein the active optical subassembly includes at least one active optical component that is mechanically coupled directly to the flex circuit and is aligned relative to the fiber receiver; and
a heat sink stiffener located on a second surface of the flex circuit opposite the active optical component subassembly and located on the second portion of the flex circuit, the heat sink stiffener being configured to stiffen the second portion of the flex circuit and act as a thermal sink for at least a portion of heat generated during operation of the active optical subassembly,
wherein the first portion including the PCB flex connection is unsupported by the heat sink stiffener and is configured to communicate electrical signals between a host system and the active optical subassembly.

2. The optical subassembly of claim 1 , wherein the active optical subassembly further includes:
an optical transmitter configured for conversion of electrical signals to optical signals; and
a monitor photodiode,
wherein the optical transmitter and the monitor photodiode are positioned entirely within the barrel cavity.

3. The optical subassembly of claim 2 , wherein:
the active optical subassembly further includes a spacer/heat spreader;
the spacer/heat spreader is positioned between the optical transmitter and the flex circuit or is positioned between the optical transmitter and the heat sink stiffener;
the spacer/heat spreader is electrically coupled to the flex circuit; and
the spacer/heat spreader is configured to transfer thermal energy generated during operation of the optical transmitter to the heat sink stiffener.

4. The optical subassembly of claim 3 , wherein:
the barrel cavity houses a plate through which an optical signal passes, and
the plate is fixed to the optical port and positioned between the active optical component and the fiber receiver.

5. The optical subassembly of claim 1 , wherein the active optical component subassembly includes:
an amplifier that is directly mechanically coupled to the flex circuit; and
an optical receiver that is positioned on the amplifier and aligned with the fiber receiver.

6. The optical subassembly of claim 5 , wherein the optical receiver includes a PIN photodiode or an avalanche photodiode (“APD”).

7. The optical subassembly of claim 1 , wherein the flex connection includes an electrically insulating connection between the optical port and the flex circuit to prohibit transfer of electrical signals between the optical port and the flex circuit and that aids in suppressing electromagnetic radiation (“EMR”) that results from operation of the an active optical subassembly.

8. The optical subassembly of claim 1 , wherein the optical port includes a plurality of side faces that are perpendicular to the flex circuit.

9. An optical subassembly comprising:
a flex circuit constructed of at least one electrically-conductive layer and at least one electrical insulator layer, wherein the flex circuit includes a printed circuit board (PCB) flex connection and a flex connection, and the PCB flex connection is included on a first portion of the flex circuit that is opposite a second portion of the flex circuit that includes the flex connection;
an optical port defining a barrel cavity and a fiber receiver configured to receive an optical fiber, wherein the optical port is mechanically coupled to the flex circuit at the flex connection on a first surface of the flex circuit;
an active optical component subassembly that is positioned within the barrel cavity and that includes at least one active optical component that is mechanically coupled directly to an optical component subassembly connection region of the flex circuit; and
a heat sink stiffener located on a second surface of the flex circuit opposite the active optical component subassembly and located on the second portion of the flex circuit, the heat sink stiffener being configured to stiffen a second portion of the flex circuit and being configured to act as a thermal sink for at least a portion of heat generated during operation of the active optical subassembly,
wherein the PCB flex connection is unsupported by the heat sink stiffener and is configured to communicate electrical signals between a host system and the active optical subassembly.

10. The optical subassembly of claim 9 , wherein the flex circuit comprises:
a top cover on which the optical port is mechanically coupled, the top cover including an insulator layer;
a core that is another insulator layer;
a bottom cover to which the heat sink stiffener is mechanically coupled;
a top conductive element that is positioned between the top cover and the core; and
a bottom metal conductive layer that is positioned between the core and the bottom cover.

11. The optical subassembly of claim 9 , wherein the active optical component subassembly includes:
an amplifier that is directly mechanically coupled to the flex circuit; and
an optical receiver that is positioned on the amplifier and aligned with the fiber receiver.

12. The optical subassembly of claim 11 , wherein the optical receiver includes a PIN photodiode or an avalanche photodiode (“APD”).

13. The optical subassembly of claim 9 , wherein the active optical subassembly includes:
an optical transmitter that is aligned with the fiber receiver; and
a spacer/heat spreader that is directly electrically coupled to the flex circuit and mechanically attached to one of the flex circuit or the heat sink stiffener, the spacer/heat spreader is configured to dissipate at least a portion of thermal energy generated during operation of the optical transmitter to the heat sink stiffener.

14. The optical subassembly of claim 13 , wherein:
the flex circuit defines at least one opening; and
the spacer/heat spreader directly contacts the heat sink stiffener such that thermal energy is transferred without moving through the flex circuit.

15. The optical subassembly of claim 13 , wherein the spacer/heat spreader includes a film resistive element configured for raising and lowering temperature of one or more components of the active optical subassembly.

16. An optical subassembly comprising:
a flex circuit constructed of at least one electrically-conductive layer and at least one electrical insulator layer, wherein the flex circuit includes a printed circuit board (PCB) flex connection and a flex connection, and the PCB flex connection is included on a first portion of the flex circuit that is opposite a second portion of the flex circuit that includes the flex connection;
an optical port defining a barrel cavity and a fiber receiver configured to receive an optical fiber, the optical port being mechanically coupled to the flex circuit at the flex connection;
an active optical component subassembly that is positioned within the barrel cavity, wherein the active optical component subassembly includes:
a spacer/heat spreader that is directly electrically coupled

Assignees

• Finisar Corp

Inventors

• Stapleton Brent
• Dwivedi Rajeev
• Walker Jr Harold Young
• Landry Gary

Classifications

• H10W72/5524

  comprising aluminium [Al] · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W90/732

  between stacked chips · CPC title

• H10W72/5525

  comprising copper [Cu] · CPC title

• H10W72/5363

  the connected ends being wedge-shaped · CPC title